Project Cerberus is a fighting game based on Lost Child visual novel RPG released by tama-soft in 2004. Its genre is listed as H-RPG (Hentai RPG).

Lost Child was one of those hentai-dialog-scroller digital novels, but stood above the rest by having a dark and gritty setting with a ton of toku stuff and a number of such superhuman chars (think Ryuki), actual battle system, and its soundtrack being composed by S.S.H, a famous Japanese composer known for heavy metal style music be it videogame based or an original piece. Here is his site to showcase his works: http://www.ssh.ne.jp/

In Lost Child game universe, armored superhuman forms are called Amitto. Instead of "Henshin!" characters yell "Conception!", and there are numerous occassions where two characters are needed to form an Amitto, with one character being a "Catalyst" to initiate transformation and other actually using the armor on his body. Well again, works similarly to Kamen Rider Double or Shirogane from Justirizers.

Aside of multiple "riders" there are more Ryuki parallels: the main hero (Cerberus) resembles Alternative Zero; And like KR series there also is an iconic spider monster (that appeared in some form in all KRs, in Ryuki very first mirror monster was the spider). Lost Child version of spider monster pretty much resembles Alien Queen from Aliens franchise. Also, the Cerberus transformation sequence seen in Lost Child/Project Cerberus openings resembles red GranSazer transformation from GranSazer opening.

Project Cerberus basically takes the cast of Lost Child with some new characters added (and spider being one of playable chars), and puts it on fighting engine. Character use Ether energy gauge, and I think their supers are called Artifact Breaks. Game's logo style resembles the logo of Dual Heroes (an old toku fighter from N64)

Project Cerberus is to be released on Naomi arcades and on PSP. On a side note, both of these platfroms were already "conquered" by emu community.

Project Cerberus youtube channel with more new vids (all but 1 character are shown)http://www.youtube.com/user/DrProjectCerberusyou can see how characters controlled by two humans can shift between basically two pilots/portraits/voices/gauges(Ether or Assault) mid-battle